


Outside Looking In

by shirasade



Category: Shadowhunters (TV)
Genre: Angst and Fluff, Bisexual Jace Wayland, Canon Gay Character, Established Relationship, M/M, POV Jace Wayland, Plot What Plot/Porn Without Plot, Polyamory, Roommates, Threesome, Voyeurism
Language: English
Status: In-Progress
Published: 2017-02-11
Updated: 2017-02-13
Packaged: 2018-09-23 12:52:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,485
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9658217
Author URL: https://archiveofourown.org/users/shirasade/pseuds/shirasade
Summary: Jace hadn’t meant to stare.





	1. Chapter 1

**Author's Note:**

> Meant to be just a bit of happy smut, my Jace feels got in the way. Sorry not sorry - it'll all turn out okay, I promise. :)

Jace hadn’t meant to stare. His plan had been to duck into his room with only a quick detour to the kitchen, yet when he walked past Magnus’s bedroom, the door stood open, giving a clear view of the massive four-poster bed - and its occupants. 

Jace froze, unable to tear his eyes from the sight that greeted him: Alec perched on Magnus’s lap, powerful thigh muscles clenching as he fucked himself on the cock disappearing into his body. Alec’s own erection stood proudly between the two rocking bodies, the hand Magnus wasn’t using to anchor Alec’s hips wrapped loosely around it. They were both sweating, soft grunts and snatches of words Jace couldn’t understand filling the air along with the slip-slide of skin against skin.

Neither one of them noticed Jace standing there like a complete idiot, knowing full well he shouldn’t be seeing this, that it wasn’t meant for anyone but the two men so completely wrapped up in each other. Yet still he found himself rooted to the spot, gawking at his parabatai and his boyfriend making love. Because that was what it was, the love between them visible in the way they held onto each other, how their eyes never once wavered from one another, and the manner in which they kept trying to kiss even as their movements became more erratic.

With a start Jace realized that he was hard in his jeans, and it was almost enough to shake him out of his stupor. Almost, because right then Alec froze, his body arching with a hoarse shout of, “Magnus!”

In fascination Jace watched cum erupting over Magnus’s fist, hitting the warlock’s smooth chest and landing in Alec’s chest hair. They had stopped moving except for Magnus’s hand, which was running down Alec’s back, petting and gentling until Alec stopped shaking. Then he lifted it to tenderly smooth Alec’s fringe to the side, the look in his eyes doing more to make Jace feel like an intruder than anything else had, and asked softly, “You ready, love?”

“Yeah, yeah...” Alec nodded, still out of breath, and Magnus’s smile turned dirty as he caught Alec in a long, deep kiss. Their tongues tangled, and Jace had to bite back a groan. It was a miracle that they hadn’t seen him yet, standing red-faced and almost painfully aroused at their door.

Then Alec rose smoothly on his knees, and Magnus’s cock slid out of his body, glistening with precum and lube. It was long and slender, and Jace was shocked to find himself wanting to touch it, taste it. He couldn’t stare at it for long, however, because Alec was scooting around on the bed until he was facing away from Magnus. This put him in a position to easily see the door, and Jace jumped to the side frantically and pressed himself against the wall, heart pounding. 

“C’mon, Magnus, now…” The impatient sound of Alec’s voice made Jace peer carefully around the corner, unable to help himself. He had one hand pressed against the hard line of his cock, but told himself it was okay as long as he wasn’t actively jerking off. Luckily, Alec’s head was turned away, towards his boyfriend, who was leaning forward to kiss him once more before breaking away to grip Alec’s hips tightly. Then he aligned himself, and although Jace couldn’t see it, the look on Alec’s face made it obvious that he was sliding back inside his boyfriend’s hole. 

They joined in a fluid motion, Alec not even flinching, even pushing backwards, and Jace dropped all pretenses, sliding his hand inside his jeans. He couldn’t hold back a small moan when his fingers touched his hard flesh, but luckily Magnus was leaning forward to half-whisper into Alec’s ear, “So good for me, my Alexander, so tight and hot… Perfect!”

Magnus was fucking Alec properly now, pulling almost all the way out and slamming back in, and Alec took it easily, smoothly. His fingers were digging into the sheets, head thrown back so Jace could see the long line of his neck, the stark black of his _deflect_ rune almost beckoning Jace to lick it. And he wanted to, wanted it so badly he could taste it, but instead he tightened his fist and fucked into his grip. Imagined it was Alec’s body hot and tight around him, until Magnus swore and came. Jace’s body clenched, suddenly overwhelmed with the desire to be the one Magnus was holding so tightly as he shook against Alec’s back, and Jace’s pants grew sticky with his release.

He slid down the wall, trusting Magnus and Alec to be too preoccupied embracing and kissing in the aftermath to hear him. Now that his mind wasn’t so clouded with arousal anymore, cold reality began to set in. What the hell had he done? As if it wasn’t bad enough that he’d intruded on something intimate, personal, and gotten off on it, he’d seen his parabatai in a way that was not only an invasion of his privacy but actually forbidden. 

Jace wasn’t blind, he’d always known Alec was attractive, and when the nature of Alec’s feelings for Jace was revealed in the aftermath of the Memory Demon, a part of Jace had wished he could reciprocate. Hurting his parabatai was the last thing he wanted, but things got so messed up between them - and when they'd reconciled Magnus had been there. Jace had been truly happy that Alec had found someone who could love him the way he deserved, especially since he himself was such a walking disaster, what with Clary, Valentine and most recently Victor Aldertree’s vendetta.

At least Jace and Alec were alright again, their bond restored, the one good thing in Jace’s life. Except here he was, curled up in the hallway of the apartment belonging to his parabatai’s boyfriend, where the warlock was magnanimously letting him stay because Jace didn't have anywhere else to go. His mind still filled with images of Alec and Magnus his eyes stung as he desperately tried to convince his body, his very soul, that this wasn’t something he wanted.

Shakily, Jace pushed himself to his feet and made his way to his room. 

***


	2. Chapter 2

Once back in his room, Jace washed himself cursorily before climbing into bed, already knowing sleep was going to elude him that night. His mind was too full, his heart too heavy, and his stomach too empty, since he’d never actually made it to the kitchen. 

He tossed and turned for what felt like an eternity, reluctant to leave the safety of his room and risk running into either Alec or Magnus, but when hunger started gnawing at his intestines, Jace sighed and gave in. As always he was only wearing briefs to bed, and normally he wouldn’t have bothered putting anything on, but this night he slipped into track pants, hesitating before putting on a hoodie, too. It made him feel slightly ridiculous to be so self-conscious, but he couldn’t help it, blushing at the thought of coming face to face with his parabatai.

As it was, he needn’t have bothered, because the flat lay quiet and peaceful, and Jace quickly made himself a sandwich, which he gobbled down together with a glass of milk. Feeling fortified and slightly more relaxed, he then walked back along the dark hallway, passing Magnus’s room. The door was still open, and despite his best intentions, Jace’s feet slowed of their own volition even before he heard Alec sigh heavily.

The sound seemed loud in the utter stillness of the night, and Jace strained his eyes, managing to make out the dark shapes on the bed. Alec’s head was resting on Magnus’s chest, and the warlock had both arms wrapped around his lover in such a protective manner, it made something deep inside of Jace clench with longing. He closed his eyes and tried to get himself to move, go back to his lonely room with its cold bed, but Magnus’s voice stopped him in his tracks.

“It’ll be alright, Alexander. I love you, and nothing will change that,” Magnus said softly, and Alec lifted his head in order to kiss him, a wealth of emotion in that simple gesture. Jace watched, helplessly rooted to the spot as the kiss deepened, although it remained slow and sweet, lacking the earlier heat. The sigh that escaped Alec when Magnus’ hand drifted down his bare back bore none of the wistfulness that had gotten Jace's attention. He was just about to finally leave, determined not to repeat his earlier mistake, when white teeth gleamed in the dark and Magnus’s spoke with a teasing smile, “And I don’t think the matter will be as difficult to solve as you think. Trust me.”

“With my life,” Alec responded immediately, easily, and Jace had to clamp down on a wave of jealousy, an ugly little voice in his head insisting that _he_ should be the one Alec put his trust in, no one else. This was good, more than good, not taking anything away from their parabatai bond, and Jace would not ruin it with his… _weakness_. Exhaling, he consciously relaxed fingers that were painfully digging into his palms and looked up, swearing to himself that this would be the last time, that he only wanted one last glance at something he hadn’t even known he wanted until that night.

He found the couple locked in another deep kiss, naked bodies sliding against each other over silk sheets as Magnus rolled them over with surprising ease. He was stronger than Jace would have thought, all sinew and muscle, and currently leaning down to suck on Alec’s neck, licking his way up until he reached his ear. Alec was stretched taut like a bow underneath him, eyes squeezed shut, panting and groaning under his boyfriend's ministrations, forcing Magnus to speak loud enough for Jace to also hear him: “Then look now, my Alexander…”

At the gentle order, Alec’s eyes flew open and landed right on his parabatai.

They were black with arousal but sharp as ever, piercing the darkness easily, and Jace could feel his face flame with shame. Bad enough that he’d been caught peeping like some creep, he became suddenly painfully aware that he’d gotten hard again at some point, something Alec’s searching gaze most definitely took in as it swept over Jace’s frozen form. It took all of his courage not to flee, figuring that an apology was the least Alec and Magnus deserved, yet the words wouldn’t come. In the end it was Alec who spoke up in a hesitant voice that held none of the anger Jace was waiting for, asking, “Jace?”

“I…” Jace swallowed, painfully pushing the words out past the lump in his throat. “I didn’t mean… I’m sorry! I’ll be gone in the morning.”

He whirled around, defeated, nothing left of the brave Shadowhunter who faced down demons on a daily basis, but was stopped once more by Magnus’s voice, calling after him, “That won’t be necessary. Just come here, it seems we need to… talk.” 

The warlock sounded firm, but again there was no anger, no disgust, and Jace managed to turn back around and obey, although his steps faltered halfway to the bed. Magnus and Alec were both sitting up, facing him, and Alec had pulled a sheet over their laps, for which Jace was grateful. He didn’t understand why neither one of them reacted the way Jace would have expected, but he didn’t know how to ask. Silence stretched between them, until Magnus broke it by rolling his eyes fondly. “Honestly, the two of you…”

The parabatai exchanged a look, and Jace’s anxiety relaxed a fraction, enabling him to admit in a small voice, “I saw you. Earlier, I mean. I know I shouldn’t have, but I did, and I’m so sorry, Alec. You too, Magnus.”

“Oh, thank you so much for including me,” Magnus laughed, sounding utterly unconcerned, and Jace flushed again. At least he definitely wasn’t hard anymore, since it felt as if all his blood was currently heating his face. Magnus’s sharp gaze softened, and he lifted Alec’s hand to his mouth, pressing a kiss to his palm before adding calmly, “And we know. I mean, we didn’t notice immediately, being somewhat… preoccupied.” Now it was Alec who blushed, and Jace hated himself for noticing how lovely he looked like this. Magnus on the other hand continued evenly, “But we did notice when you left, and it brought up some _interesting_ questions.”

He gave Alec an encouraging nudge, obviously done talking. Jace stared in dumbfounded silence, completely in the dark. What the hell was going on? Alec looked incredibly uncomfortable, wishing himself elsewhere, but then resolve sharpened his features as he came to a decision. He met Jace’s eyes head-on, and his voice only wavered a little when he asked, “Jace, do you want me? Us?” He gestured between himself and Magnus, whose warm pride was visible even in the dark of the night, and Jace swallowed, his mouth suddenly bone-dry. Alec was watching him closely, and something he saw prompted him to add quietly, “Because we want you. _I_ want you.”

“But… you have Magnus now!” The exclamation escaped unbidden, and Jace immediately wanted to take it back, hating how petulant he sounded. Wanting to remedy it, he explained quickly, “I never meant to hurt you, but I did. And you love Magnus; he makes you happy, and that shouldn’t be yet another thing I ruin!”

Magnus was watching him with a small, private smile that Jace had only ever seen directed at Alec, and it made him squirm uncomfortably. He focused back on his parabatai, taking comfort in the familiarity of Alec’s thoughtful features as he instructed quietly, “Come here, Jace.”

Jace gaped at Alec’s outstretched hand, eyes darting back and forth between it, the nervous but determined look on Alec’s face and Magnus’s enigmatic smile. He took a couple of uncertain steps towards the bed, stopping next to it. Reaching out, he touched trembling fingers to Alec’s, who turned his palm up in a clear offer. Despite the turmoil of his thoughts, Jace didn’t hesitate, sliding his hand into Alec’s grip. Immediately they both let out a shaky breath, and the heat in Alec’s hazel eyes sent shivers down Jace’s spine. He glanced nervously at Magnus, but the warlock was simply holding Alec’s other hand, nothing but amusement and approval in his face. 

Alec gave his boyfriend an adoring smile before turning back to Jace and stating seriously, “Yes, I love Magnus, and he does make me happier than I ever thought I could be. But, Jace, I love you, too - and not the way I probably should. I’m _in love_ with you still. That hasn’t gone away, no matter how hard I tried. It probably never will.” 

Clinging to Alec’s hand like a lifeline, Jace tried to wrap his mind around words that made his heart skip joyfully in his chest, and Alec responded by lifting their still-clasped hands to touch his chest with a small, private smile. Unable to help himself, Jace found himself smiling back, until Magnus interrupted their silent exchange with a wry laugh, “And dear god, did he try to get over you... So many reasons to feel guilty - because you’re straight, because the two of you are parabatai, and most recently because he got himself a wonderful Downworlder boyfriend… As if feelings are something you can just switch off.”

“I.. I take it you don’t agree?” Jace managed to ask, still overwhelmed but slowly beginning to believe that this night might not end in disaster.

It was Alec who replied, his voice full full of love and wonder, “He kept telling me that it’s okay to love more than one person, that love isn’t a finite thing. Just like I didn’t love Izzy any less when Max was born. But I figured it was all for nothing anyway, that you’d never want me that way.” He paused, seeming suddenly embarrassed again, his eyes fixed on the bedspread.

However, his grip on Jace’s hand never wavered, and it gave Jace the courage to say rather than ask, “Until tonight.” Alec nodded, still not looking up, and Jace continued, “I… I never expected to feel that way, but watching the two of you… I know I shouldn’t have, but I couldn’t look away.”

He jerked in surprise when Magnus reached over and cupped his chin in his free hand, forcing him to meet his gaze. The warlock’s eyes, ancient in a face that seemed barely older than Jace’s, were uncharacteristically serious, as he said warmly, “Yes, you shouldn’t have, but both Alec and I forgive you. Really.” The next moment Magnus’s usual demeanor was back, hiding the depth of emotion Jace had just been allowed to glimpse, and he smirked, “After all, who can blame you? We’re both very, _very_ handsome. Beautiful, even.”

Alec snorted, but his hand tightened around Jace’s, and Jace knew him well enough to hear the note of anxiety in his voice, “Whatever it was that made you look - was it real? Do you really want both of us?”

Biting his lip, Jace knew what he longed to say, but found himself paralyzed by fear. Before he could overcome it, Magnus interjected, once again easily straddling the edge between serious and light-hearted, “Or maybe you just want Alec. That would be alright, too, although I’d insist on a fair and balanced custody agreement.”

Being old and wise certainly had its advantages, Jace thought confusedly, even as Alec made a protesting noise that Magnus shushed with a peck on the lips, before telling him gently, “Yes, Alexander, really. I love you, and I must admit to being more than a little intrigued by your parabatai, but if it’s only you he wants, I would never stand in the way of your happiness.”

Alec still looked slightly unhappy, but they’d obviously had this discussion before, and after a long look into Magnus’s eyes he nodded in acquiescence, leaning in for another kiss. This one went on for quite a while, their lips sliding against each other sensuously. Jace wondered if he was supposed to leave, but Alec was still holding onto his hand, and like before Jace found himself captivated by the sight before him. However, for the first time there was no bitter taste in his mouth as he allowed himself to imagine being part of this instead of on the outside.

He also realized that, as much as he wanted to know what Alec tasted like, he was also more than a little _intrigued_ , as Magnus had put it, by the warlock’s lips, wondering if they were as soft as they looked. A loudly cleared throat tore him from his reverie, and he noticed with a blush that Alec and Magnus had stopped kissing and were watching him intently. Magnus appeared to already know what was going on in his head, if the grin on that kissable mouth was any indication, and Alec… Jace’s breath caught at the look in his parabatai’s eyes, and without thinking he leaned in and pressed his lips to Alec’s, feeling them part in surprise.

Instead of deepening the kiss, however, Jace moved slightly away and rested his forehead against Alec’s. Their bond was warm and alive between them, and Jace breathed in his parabatai's familiar smell before saying the words that would change everything, his voice surprisingly steady: “Yes. Yes, Alec, I want you.” Before Alec had the chance to respond, he turned to Magnus and added quickly, with a slightly uncertain smile, “And you. I want you both. At least, I’m pretty sure.”

Magnus didn’t seem put out in the least, because he just smiled back, nodding, “Well, I think we can work with that.”

With that he leaned in and kissed Jace, barely more than a peck, but when they parted, Alec was staring at them with such wonder in his eyes, Jace would have agreed to anything, even if his lips hadn’t been tingling in anticipation of more. More Magnus, more Alec, more _everything_. Feeling giddy with a mix of sheer relief and unexpected happiness, he pulled his parabatai forward until he was practically in his lap, but it was Alec who captured his lips with his own, all hesitation forgotten. An eager tongue demanded entrance into Jace’s mouth, and next to them, Magnus chuckled, making Jace shiver when warm hands trailed down his sides, nimbly unzipping his hoodie. Alec groaned into their kiss, and Jace opened his eyes to see Magnus suck on his boyfriend’s neck, obviously a very sensitive spot, something Jace filed away for later.

Then Alec's fingers found Magnus’s hand on Jace’s chest, teasing his nipples, and Jace’s eyes slid shut again, conscious thought fleeing as sensation took over.

**Notes for the Chapter:**

> I hadn't planned on there being this much talking, but it felt necessary - next chapter will be threesome smut, I promise. :)


End file.
